Hair felt and method of making



Patented June 19, 1928.

UNITED STATES 7 1,673,967 PATENT OFFICE.

ALBERT L. CLAPI, OF DANVER S, MASSAGHU SETTS ASSIGNOR T0 BECKWITH MANU-FACTURING COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSA-GHUSETTS.

HAIR FELT AND METHQD 015 l/IdKENG.

Ho Drawing.

resins, gums, etc. of such nature and in such proportion as-inay bedesired to give it characteristics suitable for roofing, flooring, shoestiffeners, or other products composed of saturated fibrous material.

The principal difficulty found in the use of large quantities of longhair suc i as that comprising goat and cattle hair as it comes fromtanneries is the strong tendency of the hair to become matted and lumpyin the machine so that uneven felt having weak spots therein isproduced, and in attempts heretofore to produce a felt containing suchhair, it has been necessary to .set the beater roll down so hard inbeating out these lumps, that most of the hair has been cut or brokenand consequently in the felt the hair was relatively short. The morelong hair that can be incorporated in the felt, however, the more porousthe product and the stronger and tougher when saturated.

l have discovered that considerable quantities of hair may besuccessfully used to produce substantially uniform felt containing thehair in its original length, if in connection therewith some agent isused to in dividualize the hair while the furnish is being prepared forfelting. One such material which may be employed is short hair treatedwith caustic soda to form a slimy mass which coats the individual longhairs and permits them to slip on each other. As an example of the wayin which this may be used, the procedure ma be as follows: twenty partsby weight 0 rags or other cellulosic material, thirty parts of goat orcattle hairas it comes. from the tannery, and six parts of caustic sodaare placed in a beating engine with suflicient water to perunitcirculation, and are beaten with the beater roll down hard until thehair is quite short and the mixture forms a slimy mass. Fifty parts oflong goat or cattle hair are then added and the mixture beaten out toform a homogeneous mass with the beater roll raised just sufiicientl sothat the hair last added is kept long ut is combed out Application filedSeptember 12, 1923. Serial Ito. 662,226.

and coated with the other material. If the individualizing agent is notused it is impossible to maintan the major porton of the long'liair inits original length and yet separate it suificiently to felt properly onthe paper machine. By theuse of this individiia'lizing agent, however,and by careful adjustment of the beater-roll, the hair may becombed outand coated with the individualiring material while maintained in itsoriginal length. Eight parts of alum may then be added to the mxturewhich causes the slimy gelatinous mixture of short hair and hair whollyand partially dissovled in the caustic solution to he precipitated onthe long hair. The stock may then be run into the vat of the papermachine and sheet-ed in the usual manner.

The presence-of the short hair and also the precipitated matter causesthe felt to be somewhat more dense than would be the case if they werenot present and it also adds materially to the ease with which the stockis handled in the papermachine since they act to prevent theindividualized fibers from matting together or becoming displaced afterhaving once been felted in the paper machine, pressure exerted thereonby the various pressure rolls being then inedective tocause displacementof the fibers. This precipitated matter also acts to impart body to thefelt much increasing its strength when in dry condition. Practically allthe individualizing agent so precipitated is aluminum gelatinous.hydrate. The short hair alone also has some individualizing propertieseven though it is not completely dissolved by the caustic and theindividualizing agent is thus composed of a mixture of short hair andgelatinous slimy material.

In place of the rags, a mixture of rag and sulphite pulp. or sulphatepulp alone may be employed and if it be desired to impart a more opentexture to the material this may be effected by adding up to ten partsof woodflour or fine sawdust, preferably before the addition of thatportion of the hair which is tobe kept long in the final product. Thiswood'flour or sawdust causes the stock to be freer and makes thesaturating of the product somewhat easier. The quantity of sulphate pulpor other cellulosic ma terial, may be reduced if desired to as little as10% and when this is done 20% of hair ill iltlt which is beaten up shortwith the caustic to form an individualizing agent may be employedtogether with 70% of long hair. A small amount of cellulosic fiber suchas rags, chemical wood pulp, or screenings appears necessary in orderthat the stool: may be caused to run successfully on the paper machine.

The action of the caustic on the short hair is evidently partially tosaponify the oil of the short hair fibers and partially to dissolve thehair, and to form a slimy mass which Surrounds and coats the long hairsand causes them to slip by each other and become thoroughlyindividualized and evenly distributed throughout the stock in thebeater.

Hair as it comes from the tanneries is usually matted and lumpy. Duringthe process of de-hairing hides in the tanneries lime is usually usedand the hair as it comes from the de-hairing operation is wet and mixedwith lime. As this mixture does not keep, it is the usual practice towash out the lime and then dry the hair. Some lime may, however, be leftin the hair in its dry state. The resence of such lime, when carryingout tlieprocess of this invention does no harm, but indeed is often ofdistinct value since a cheaper grade of caustic may be used, the cheapergrades of caustic usually containing a considerable portion of sodiumcarbonate which is causticized by the lime into caustic soda. Duringthis action the lime itself is converted for the most part intoinsoluble salts which are retained by the gelatinous matter precipitatedby the alum, and act as a filler for the final product. Unwashed hairmay thus be used successfully in the process of this invention with thecheaper grades of caustic when itv can be procured sufficiently promptlyfrom the tannery to avoid spoiling, but washed hair may be employed withsubstantially the same results if lime be added to the beater. Where theunwashed hair can be obtained, however, it should be somewhat cheaperthan the washed hair.

Having thus described this invention it should be evident to thoseskilled in the art that various changes and modifications might be madetherein without degiirting from its spirit or scope as defined y theappended claims.

I claim:

1. Felt having the characteristics of wet paper machine fabrication,said felt comprising hair of original length, short hair, and cellulosicmaterial.

2. A method which comprises beating out hard a mixture of cellulosicmaterial, hair, and caustic until the hair short: or partially dissolvedto a slimy state, then adding long hair, beating out the long hair whileret aining its original length until it is individualized by themixture, and then felting the stock on a paper machine.

3. The method which comprises individualizing long hair with a mixturecontaining short and partially dissolved hair, and then felting thestock on a paper machine.

4. The method which comprises individualizing long hair with a mixturecontaining short and partially dissolved hair reduced to a slimy state,and then felting the stock on a paper machine.

5. The method which comprises mixing long hair and an individualizingagent comprising short hair, and felting the stock on a paper machine.

6. The method which comprises mixing long hair and a gelatinousindividualizing agent comprising partially dissolved hair, and feltingthe stock on a paper machine.

7. The method which comprises mixing long hair with an individualizingagent com prising short hair and caustic, and felting the stock on a paer machine.

8. The metho which comprises mixing long hair with cellulosic materialand an indlvidualizing agent comprising short hair and caustic, andfelting the stock on a paper machine.

9. The method which comprises mixing long hair with an individualizingagent comprising partially dissolved hair forming a gelatinous mixture,and felting the stock on a pa er machine.

10. T e method which comprises mixing long hair with an individualizingagent comprising short hair and caustic, precipitating theindividualizing agent on the hair, and felting the stock on a papermachine.

11. The method which comprises mixing long hair with cellulosic materialand an individualizing agent comprising short hair and caustic,precipitating the individualizing agent on the cellulosic material andlong hair, and felting the stock on a paper machine.

In testimony whereof I have aitixed my signature.

ALBERT L. CLAPP.

